I. Field
The following description relates generally to wireless communications, and more particularly to transmitting control information over wireless communications channels.
II. Background
Wireless communication systems are widely deployed to provide various types of communication content such as, for example, voice, data, and so on. Typical wireless communication systems may be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g. bandwidth, transmit power, . . . ). Examples of such multiple-access systems may include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long-term evolution (LTE), 3GPP2, ultra mobile broadband (UMB), etc.
Generally, wireless multiple-access communication systems may simultaneously support communication for multiple mobile devices. Each mobile device may communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations may be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth. In addition, mobile devices can communicate with other mobile devices (and/or base stations with other base stations) in peer-to-peer wireless network configurations.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. The antennas can relate to both base stations and mobile devices, in one example, allowing bi-directional communication between the devices on the wireless network. Base stations can be heterogeneously deployed such that a mobile device can connect to a base station, or other access point, that may not be the most desirable base station from the standpoint of signal strength or quality. For example, a residential home based access point can be used by a mobile device for reasons related to security, service availability, etc.; however, the access point can be physically near a base station with a greater signal strength that can interfere with the communication between the mobile device and access point. The converse can be true as well where a device communicating with the base station comes in range of the residential access point. Thus, the interference can be less consistent, and therefore less predictable, than in conventional deployments.